Impact of precipitation on aerosols index over selected stations in Iraq using remote sensing technique

Abstract

Aerosol Index (AI) data extracted from the Ozone Monitoring Instrument (OMI) with spatial accuracy of 0.25° × 0.25° covering Iraq and surrounding regions (27.5°–38.5°N, 38°–49.25°E) have been examined within the period from January 2003 to December 2013. The results presented considerable variability of AI monthly mean in spatial and temporal scale, with higher values at the southern regions and lower values over northern Iraq. The annual average AI in the north, middle and south regions of the country have been found to be 0.635 ± 0.207, 0.950 ± 0.263 and 1.265 ± 0.326, respectively with an overall average of 1.080 ± 0.377 over the whole of Iraq. The monthly spatial average values of AI showed a significant maximum during the month of May, June (1.323 ± 0.565) (1.42 ± 0.603), these two months having the highest dust loading activity over the region, and minimum value in the month of December, January (0.774 ± 0.180) and (0.758 ± 0.190), showing a minimum level performance of dust loading processes. We also examined the impact of precipitation on AI values and the significant remark of this examination was that a reverse correlation exists between AI and accumulated rainfall, particularly within late fall (November) and two winter months, December and January with corresponding R2 values of 0.662, 0.630, 0.501,0.627, 0.587, 0.530 and 0.471, 0.513, 0.498 for Mosul, Baghdad and Basrah Consecutively.